package com.itheima.neibulei4;

public class Demo01 {

    public static void main(String[] args) {
        class Inner {
            int j;

            public void sing() {
                System.out.println("sing");
            }
        }
        Inner inner = new Inner();
        inner.j = 20;
        System.out.println(inner.j);
        inner.sing();
    }
}
